1. Field of the Invention
This invention relates to a camera having a multifocus detecting device for detecting the defocus amounts of a plurality of object areas and effecting focus detection.
2. Description of the Related Art
As a focus detecting device in a camera, there is well known a method of causing light beams from an object area passed through the different exit pupil areas of a photo-taking lens to be imaged on a pair of line sensors, and finding the amount of displacement of the relative position of a pair of image signals obtained by photoelectrically converting an object image, to thereby detect the defocus amount of the object area. Also, in the above-described method, there have been a number of methods of preparing a plurality of sets of focus detecting systems (optical systems and sensors) to thereby detect the defocus amounts of a plurality of object areas.
When the detection of the defocus amounts has been effected for said plurality of areas, distance measurement for the plurality of object areas is effected, but since final focus adjustment is directed to an object for one distance measurement area, means for selecting or manually selecting an object area on some judgment conditions from among the plurality of areas is provided on the camera side so that focus adjustment may be effected for one of the object areas.
In this case, there occurs the inconvenience that which area is the selected area cannot be known.
In order to solve this problem, it is necessary, for example, to dispose an indicating means for indicating the selected area in a viewfinder to let the selected area, i.e., the focus-adjusted area, be known. On the other hand, if the construction as described above is adopted, one of a plurality of areas is selected and only that area is indicated and thus, even when there are areas which exhibit defocus amounts approximate to the defocus amount in said selected area, only one area is indicated, and in spite of the fact that objects in a plurality of areas originally exhibit the same or substantially the same defocus amount and if the camera is focused on the object in one of those areas, the camera is also in focus on the objects in the other areas, the photographer becomes unable to know it. Also, when the objects in the respective areas are substantially at the same distance, the area selected changes each time the focus detecting operation is repeated, and the area indicated changes each time, and this leads to the possibility that the photographer thinks that focus detection is done unstably.